Field of the Invention
The present invention is directed in general to communications systems and methods for operating same, and more particularly to card toolkit support for Internet Protocol (IP) multimedia subsystems within communications systems.
Description of the Related Art
In known wireless telecommunications systems, transmission equipment in a base station or access device transmits signals throughout a geographical region known as a cell. As technology has evolved, more advanced equipment has been introduced that can provide services that were not possible previously. This advanced equipment might include, for example, an E-UTRAN (evolved universal terrestrial radio access network) node B (eNB), a base station or other systems and devices. Such advanced or next generation equipment is often referred to as long-term evolution (LTE) equipment, and a packet-based network that uses such equipment is often referred to as an evolved packet system (EPS). An access device is any component, such as a traditional base station or an LTE eNB (Evolved Node B), that can provide a user agent (UA), such as user equipment (UE) or mobile equipment (ME), with access to other components in a telecommunications system.
In mobile communication systems such as an E-UTRAN, the access device provides radio accesses to one or more UAs. The access device comprises a packet scheduler for allocating uplink (UL) and downlink (DL) data transmission resources among all the UAs communicating to the access device. The functions of the scheduler include, among others, dividing the available air interface capacity between the UAs, deciding the resources (e.g. sub-carrier frequencies and timing) to be used for each UA's packet data transmission, and monitoring packet allocation and system load. The scheduler allocates physical layer resources for physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) data transmissions, and sends scheduling information to the UAs through a control channel. The UAs refer to the scheduling information for the timing, frequency, data block size, modulation and coding of uplink and downlink transmissions.
In certain mobile communication systems, there is a requirement for a universal integrated circuit card (UICC) application (e.g., a subscriber identity module (SIM), an Internet Protocol (IP) multimedia subsystem (IMS) SIM (ISIM), and a universal terrestrial radio access network (UTRAN) SIM (USIM)) may make use of Internet Protocol (IP) multimedia subsystem (IMS) functionalities controlled by mobile equipment (ME). See e.g., 3GPP TS 22.101. For example, FIG. 1, labeled Prior Art, shows a block diagram of an operation where a UICC application invites a peer to a session. FIG. 2, labeled Prior Art, shows an example of a UICC to IMS channel establishment operation. FIG. 3, labeled Prior Art, shows an example of a UICC to IMS communication. In this example, an IMS UICC user initiated registration is performed where an IMS Subscriber Identity module (ISIM) is present.
It is possible that UICC to ME commands may include an open channel for IMS function which extends known Bearer Independent Protocol (BIP) commands for IMS like Close Channel, Send data, Receive data and Get Channel Status to allow the channel to use the IMS as a means to send and receive IMS traffic to and from the UICC.
In certain known systems (e.g., 3GPP 31.111 v. 9.1.0) the UICC can use the Open Channel request to activate a PDP Context and to send IP data from the UICC to the network on an access point name (APN) chosen by the UICC. This function is in place under hospices of BIP that would allow for IP based over the air (OTA) updating of the UICC to replace the aging short message service (SMS) push and SMS transport currently in use.
The Open Channel request can present challenges where the UICC is another IMS application on the UE. Because like other applications this IMS application requires specific registration with the IMS service. FIG. 4, labeled Prior Art, shows an example of how the UICC does not have knowledge of what is occurring at the IMS layers. FIG. 5, labeled Prior Art, shows a flow diagram representing how IMS deregistration indication does not contain clear cause/reject indications of why this deregistration occurred in the first place.